Epidemiology of Nemaline Myopathy
Overall Nemaline Myopathy Prevalence
The estimated prevalence of nemaline myopathy in the general population is approximately 1 in 26,000 to 28,000 individuals 1.
This makes nemaline myopathy one of the more common congenital myopathies, though it remains a rare disease overall 1.
The incidence has been estimated at approximately 1 in 50,000 live births, though this figure may vary by population and detection methods 2.
NEB-Related Nemaline Myopathy Epidemiology
Mutations in the nebulin gene (NEB) represent the most common genetic cause of nemaline myopathy, accounting for approximately 50% of all genetically diagnosed cases 1, 3, 4, 2.
Key Epidemiologic Features of NEB-Related Disease:
NEB mutations are the single most frequent causative gene in nemaline myopathy cohorts, with studies consistently reporting that nebulin accounts for roughly half of all cases 3, 4, 5, 2.
In a Chinese neuromuscular center cohort, 73.33% (11 of 15 patients) had NEB mutations, suggesting potential geographic or ethnic variation in the relative frequency of causative genes 5.
The nebulin gene is exceptionally large and complex, making it technically challenging to sequence and potentially leading to underdiagnosis in some populations 3, 4.
Clinical Severity Spectrum in NEB-Related Cases:
NEB-related nemaline myopathy demonstrates marked phenotypic heterogeneity, ranging from severe/lethal neonatal forms to mild adult-onset presentations 4, 5.
Severe forms with neonatal death and arthrogryposis have been documented with specific NEB mutations that drastically reduce nebulin protein levels 3.
The level of nebulin protein expression appears to correlate with disease severity, with lower protein levels associated with more severe clinical phenotypes and greater impairment of muscle force generation 3.
Intermediate forms presenting in infancy and typical/mild forms presenting in childhood or adulthood represent the majority of NEB-related cases 4, 5.